Mica press ram with hydraulically operated punch and stripper means



Dec. 1, 1959 H. w. ROEBER 2,914,981

MICA PRESS RAM WITH HYDRAULICALLY OPERATED PUNCH AND STRIPPER MEANS Filed June 5, 1957 2 She ets-Sheet 1 T IT lFH'lI IT I (MICA PUNCH INVENTOR HENRY W. ROEBER ATTORNEY Dec. 1, 1959 H. w. ROEBER 2,914,931

MICA PRESS RAM WITH HYDRAULICALLY OPERATED PUNCH AND STRIPPER MEANS 2 Sheets-Sheet 2 Filed June 5, 1957 INVENTOR HENRY w. ROEBER BY A TTORNEY United States Patent MICA. PRESS RAM WITH HYDRAULICALLY OPERATED PUNCH AND STRIPPER MEANS Henry W. Roeber, Emporium, Pa., assignor, by mesne assignments, to SylvaniaElectric Products Inc., Wilmington, Del., a corporation of Delaware Application June 5, 1957, Serial No. 663,724

4 Claims. (Cl. 83-140) This invention relates to hydraulic punching devices and more particularly to stripping devices used therewith.

An object of this invention is to provide a punch and stripper suitable for inclusion in high speed automatic equipments.

A further object of this invention is to provide a stripper having, initially, a low contact pressure and, subsequently, a high stripping power for use in combination with a hydraulic punch.

Another object of this invention is to provide a hydraulic punch and stripper which is of unitary construction.

A still further object of this invention is to provide a stripper which does not retard the rapid advance of the punch but which. applies full stripping force to the work when said punch is withdrawn from the work.

Other objects and advantages of the invention will be apparent during the course of the following. description.

In the accompanying drawings, forming a part of this application, and in which like numerals are employed to designate like parts throughout the same:

Fig. 1 is a diagrammatic view of a machine layout indicating the punch press station particularly described and claimed herein,

Fig. 2 is a sectioned side elevation of a punching, device with stripper mechanism embodying the invention,

Fig. 3 is a view along a line 3--3 of Fig. 2 showing the tooling and method of mounting same and Fig. 4 is a fragmentary plan view of the embodiment.

Referring to the drawings, in Fig. 1 is diagrammatically illustrated a machine for automatically assembly electron tube mounts at successive stations indicated as A, 'B, C etc. The device herein claimed is located at station A. At this station insulating, discs are indexed between a disc perforation mechanism and the perforated discs transferred to the indexible carrier L of the machine. Since the matter just described is not material to the understanding of the invention, except as set forth, no further details need be described.

Referring to Fig. 2, the punching device comprises a base supported frame 4 forming part of the hydraulic punch and stripper combination. The main or primary hydraulic cylinder 6 is part of this frame. The upper end of the cylinder, as viewed in Fig. 2, is closed-by a 0nd cylinder is vented through-a passageway within the lower portion 16 of the main: ram and terminates in. a port .29. Within the aforementioned sleeve 28 is contained a spring 30 and a plunger 32 which is retained within a slotted portion 34 of the sleeve by a pin 36. The functioning of this arrangement will be more fully described under the description of the operation of the entire apparatus.

Attached to the upper portion 14 of the main ram is .a retaining collar 38. This collar acts as' a driven element for rollers 40 which aremounted on a yoke 42 of a ram lift arm 44 which in turn is connected by a link 46 to lift cam 45 which is mounted on a shaft 47 driven from the main machine.

That portion of the inner ram 24' which extends beyond the end of the upper portion of the primary or outer ram .10 passes through a support member 48 mounted on the cylinder head and is thereequipped with. a stop 50.

Securedto the lower end 16 of the main ram is the upper die shoe of the die set 102,. as shown in Figs.v 2 and 3. The die shoe is secured. to the ram by a pair-of L-shaped lugs 104, mounted. on thedie shoe by bolts 106, and each having a horizontal portion 107 entering into a recessed groove 108 in the ram. Within this die set is mounted a plug stop 110 whichis in contact at its upper surface only with spring biased. plunger 32. Located at the lower end of the plug stop is a stripper pin anchor block 112 to which are connected stripper pin 114. The stripper pins pass through an upper die block 116,. a pressure pad 118, and a punch holder terminating in a stripper pad 122. The motion of the parts is restricted to vertical rectilinear motion by a pair of base mounted posts 124 on which the upper die shoe slides. Closure of the die set is prevented during shut down of the machine by safety stops 126, which are extended on shut down. During normal machine operation, the stops are lowered from. the positions shown in Figs. 2 and 3. Positioned beneath punch 127 and the stripper arrangement 122 is a lower die block 128. Located between the upper and lower halves of the dieset are a turret feed disc 1'30 and a transfer arm 132. The functions of the lasttwo named devices will be more fully explained herein in the description of the operation of the apparatus. to follow.

The disc turret feed 130, see Figs. 2 and 4, is mounted on a vertical shaft 134, freely rotatable in a bearing 136, mounted on the base of the machine, the lower face of the turret being provided with circularly spaced cam follower rollers 138 engageable with a. barrel cam 140' mounted ona shaft 142 geared with shaft 47. On shaft 142 there is also fixed a cam 144 driving the transfer arm 132 through a linkage 146. Sincethe mechanism for indexing the turret and operating the transfer arm formno part of this invention, no further description thereof need be given;

The machine isstarted with the safety stops 126*re-f tracted, with the main ram 10in the uppermost position cylinder head 8 through which passes the main ram 10 1 and a fluid inlet 12. The main ram 10 is constructed of an upper portion 14 joined to a lower portion 16 by bolts 18. A fluid outlet 20 is also provided in main cylinder 6. The lower portion 16 of the main ram is so constructed that. a second cylinder 22 is formed therein, while released from the action of the ram lift arm 44, with the. turret disc 130' indexed to the proper position, and with insulating discs positioned in openings in the turret feed disc. Operation of a valve controlled by a cam, not' shown, on the main shaft of the machine, not shown; allows the entrance of fluid pressure through the port 12 into the main cylinder 6. This fluidpressure exerts a; force upon the main ram 10 causing it to descend.

The inner ram 24' is in its upper position inits cylinder 22 due-to the force exerted thereon by the spring 30 which is contained in thesleeve portion 28; This spring pressure: also forces the plunger 32 to itsilower position causing the pin 36 to ride close tothe'bottom of the slot 34. This form of lost. motion connection or bias may 318013611910. vided by a fluid pressurearrangement. The plunger in! this position extends beyond the end of the sleeve forcing 132 and to seat it against the lower die block 128. This seating force may also be developed by fluid pressure means operating on the plunger 32. When the disc is thus seated continued descent of the main ram 10 causes the punch 127 to pass through the stripper pad 122 into the die block to pierce the disc. The descent of the ram assembly with the stripper pad restrained by the lower die block causes a slight compression of the spring 30 which is insuflicient as a stripping force. With this arrangement rapid approach by the punch is possible without the retardation due to stripping force build-up, as is now known in the art. However since rapid withdrawal of the punch is desired without disturbing the seating of the insulating disc in the transfer arm, additional stripping force is required. This increased force is obtained by admitting fluid pressure through a cam controlled valve, not shown, which is mounted on the main shaft, into the inlet 26 to the upper surface of the inner ram 28. This pressure causes the inner ram to descend and the sleeve 28, which is fixed to the ram, is thus lowered.

This movement of the sleeve relative to the spring biased plunger 32 causes the pin 36 to ride up in the slot 34. This relative movement results in the further compression of the spring 30 thus increasing the force applied to the stripper pad 122 through the connecting parts hereinbefore described. This increased force may be developed by applying fluid pressure to the plunger 32.

The fluid pressure in the main cylinder is discharged concurrently with the operation of the ram lift arm 44 through the linkage 46 which causes the yoke 42 to lift. This lifting action causes the rollers 40 to contact and force the collar 30 upward, thus producing a lifting action which causes the entire ram assembly to move from its lowered position. The punch 127 withdraws through the perforated insulating disc 150 and stripper pad 122. The stripper pad, due to its increased stripping force, retains the insulating disc in its described position in the transfer arm 132. After the stripper pad has been displaced from the insulating disc 150, due to the upward movement of the main ram, the fluid pressure holding the inner ram 28 in its lowered position is released and the spring 30 forces this ram to resume its upper or raised position in readiness for its next cycle of operation. The stripper pad once again is held in its extended position by the initial force of the spring 30 alone.

stripper slidable with respect to the punch, means for operating the stripper comprising a spring within said second sleeve, a plunger within the sleeve under the influence of the spring, a lost motion connection between the plunger and the sleeve, means interconnecting the plunger and the stripper, and means for mechanically moving the first hollow ram in the opposite direction to an initial inoperative position.

2. In a punching machine, a support, an outside cylinder carried by said support, a hollow first r-am within said cylinder having a first, upwardly extending sleeve, a collar fastened adjacent the upper end of the sleeve, lifting means engageable-with the collar therebeneath to raise the collar and the first ram, a second sleeve, extending downwardly from the first ram, an upper die shoe carried by said second sleeve, a second ram within the first hollow ram having an upwardly extending hollow shaft, a stop element near the top of the shaft, a fixed abutment therebelow to be engaged by the stop element, a third sleeve extending downwardly from said second ram passing through said second sleeve, a spring housed within the third sleeve, a plunger slidably connected with and within said third sleeve, said spring reacting against said plunger and said third sleeve, a stripper pad mechanism slidably mounted within said upper die shoe and engaged by said plunger, a punch carried by said upper die shoe, a stripper pad carried by said stripper pad mechanism, said stripper pad being slidable with respect to the punch, a lower die shoe for supporting an article cooperating with said punch and stripper pad, means for applying fluid pressure above the first ram, means for applying fluid pressure above said second ram through the hollow shaft and means for venting the space below said first and second rams.

3. In a punching machine, a support, an outside cylinder carried by said support, a hollow first ram within said 7 cylinder having a first upwardly extending sleeve, a collar After the ram lift arm 44 has reached its highest posi- 7 tion, it descends at once leaving the main ram 10 held in its upper position solely by friction, this action being due to the contour of the lift cam 45. The turret 130 then indexes to the next position while the transfer arm transfers the punched disc to a holder on the conveyor 2 at the station and returns to its position beneath the feed turret. Thus the unit is ready for its next sequence.

What is claimed is:

1. A support, a cylinder carried by the support, a first hollow ram therein, a second ram within the hollow of the first ram, a sleeve movable with said first ram, a second sleeve within said first sleeve movable with said second ram, means for admitting fluid pressure to the cylinder to'move said first ram to a punching position, means for admitting fluid pressure to and from the hollow ram to move the second ram therein, a die block carried by the first sleeve, a punch mounted in the die block, a

fastened adjacent the upper end of the sleeve, lifting means engageable with the collar therebeneath to raise the collar and the first ram, a second sleeve, extending downwardly from the first ram, an upper die shoe carried by said second sleeve, a second ram within the first hollow ram having an upwardly extending hollow shaft, a stop element at the top of the shaft, a fixed abutment therebelow to be engaged by the stop element, a third sleeve extending downwardly from said second ram passing through said second sleeve, a spring housed within the third sleeve, a plunger slidably connected with and within said third sleeve, said spring reacting against said plunger and said third sleeve, a force transmitting plug slidably mounted within said upper die shoe and engaged by said plunger, a stripper anchor block slidably carried by said upper die shoe, said anchor block carrying pins connecting to a stripper pad, a punch carried by said upper die shoe, said stripper pad being slidable with respect to the punch, a lower die shoe for supporting an article cooperating with said punch and stripper pad, means for applying fluid pressure above the first ram, means for applying fluid pressure above said second ram through the hollow shaft and means for venting the space below said first and second rams.

4. In a punching machine, a support, an outside cylinder carried by said support, a hollow first ram within said cylinder having a first, upwardly extending sleeves, a collar fastened adjacent the upper end of the sleeve, lifting means engageable with the collar therebeneath to raise the collar and the first ram, a cam for controlling said lifting means and contoured to raise the first ram after the punching operation and to withdraw the lifting means when the first ram has been fully retracted and prior to the application of fluid pressure to the first ram, a second sleeve, extending downwardly from the first ram, an upper die shoe carried by said sleeve, a second ram within the first hollow ram having an upwardly extending hollow shaft, a stop element at the top of the shaft,

a fixed abutment therebelow to be engaged by the stop element, a third sleeve extending downwardly from said second ram passing through said second sleeve, a spring housed Within the third sleeve, a plunger slidably conthe hollow shaft and means for venting the space below said first and second rams.

References Cited in the file of this patent UNITED STATES PATENTS 2,118,648 Johnson May 24, 1938 2,215,643 Gorham Sept. 24, 1940 2,364,011 Wales Nov. 28, 1944 2,642,138 M'acewka June 16, 1953 10 2,699,830 Hodge Jan. 18, 1955 FOREIGN PATENTS 116,236 Great Britain June 6, 1918 

